The instant invention pertains to methods and apparatus for measuring a person's knee laxity.
Human knee joints may range from being very tight to being very loose. Generally, whether a knee joint is tight or loose depends upon the qualities of the cartilidge in the knee joint as well as on the muscles which support the joint. Knee joints which are either very loose or very tight are subject to injury. If the laxity of the knee joint is known and if it is considered to be too tight or too loose, appropriate treatment may be administered to remedy or at least reduce the severity of the condition. It is therefore desirable to be able to quantify the laxity of human knee joints.
The instant apparatus includes means for fixing a person's knee. Also included is means for selectively applying force against the lateral (outside) or against the medial (inside) portion of the tibia. When the force is so applied, measuring means measure the amount of tibia movement. The correlation of tibia movement with the amount of force required to generate such movement provides an indication of knee laxity. The application of force and movement measurement may be made at varying degrees of knee flexion.
It is therefore a general object of the instant invention to provide an indication of knee laxity by correlating the amount of tibia movement with the amount of force necessary to generate such movement.
It is a more specific object of the instant invention to provide such an indication with force being applied to the tibia in a plane substantially parallel to the medial-lateral plane.